Patents by Inventor Hiroshi Mizusawa

Hiroshi Mizusawa has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 7313347
    Abstract: A cleaning device, a process cartridge, an image forming apparatus, and toner to maintain improved cleaning performance for a long time. The cleaning device includes a cleaning blade, a lubricant applying part, and a toner removing part. The cleaning blade is disposed in contact with a surface of an image bearing member. The lubricant applying part coats a solid lubricant on the surface of the image bearing member, and is disposed in an upstream side from the cleaning blade with respect to a rotational direction of the image bearing member. The toner removing part removes toner particles, and is disposed in an upstream side from the lubricant applying part with respect to the rotational direction of the image bearing member.
    Type: Grant
    Filed: August 22, 2005
    Date of Patent: December 25, 2007
    Assignee: Ricoh Company Ltd.
    Inventors: Takeshi Shintani, Takuzi Yoneda, Ken Amemiya, Takaaki Tawada, Tokuya Ojimi, Toshio Koike, Yuji Arai, Masanori Kawasumi, Masami Tomita, Hideyo Watanabe, Satoshi Takano, Haruji Mizuishi, Hiroshi Ono, Hiroshi Mizusawa, Satoshi Hatori, Takeshi Tabuchi, Akira Fujimori, Kaoru Yoshino
  • Patent number: 7177555
    Abstract: The image forming apparatus comprises a photoconductor, a latent electrostatic image forming unit for forming a latent electrostatic image on the photoconductor, a developing unit for developing the latent electrostatic image using a developer comprising a toner to form a visible image, a transfer unit for transferring the visible image to a recording medium, a cleaning unit for removing the developer remained on the photoconductor surface and a developer amount detection unit for detecting developer amount adhering to the photoconductor surface by a reflecting photosensor, wherein the developer stirring time per copy when one copy is made from an original, is 2 to 6 times the developer stirring time per copy when two or more copies are made from the original, wherein the toner comprises at least a binder resin and a wax, and the dynamic frictional coefficient of the toner is 0.15 to 0.45.
    Type: Grant
    Filed: January 15, 2004
    Date of Patent: February 13, 2007
    Assignee: Ricoh Company, Ltd.
    Inventors: Bing Shu, Mitsuo Aoki, Haruji Mizuishi, Mikio Ishibashi, Masaru Tanaka, Shinji Tamaki, Hiroshi Mizusawa, Shin Hasegawa
  • Patent number: 7139503
    Abstract: A cleaning apparatus includes a brush member to be brought into contact with a member to be cleaned to remove toner particles attached to the member. The brush member includes a conductive material.
    Type: Grant
    Filed: October 17, 2003
    Date of Patent: November 21, 2006
    Assignee: Ricoh Company, Ltd
    Inventor: Hiroshi Mizusawa
  • Patent number: 7068960
    Abstract: A cleaning device includes a brush roller that removes deposit from a surface of a member to be cleaned by rotating due to a movement of the surface of the member. The brush roller includes a rotary shaft element and a brush provided on the rotary shaft element. The brush abuts the surface of the member due to a weight of the brush roller. The brush includes filaments, and the brush roller satisfies the inequation Y/X?2.8, where Y is a diameter (denier) of each of the filaments, and X is a length (mm) of each of the filaments. The filaments slant with respect to a normal direction of the rotary shaft element.
    Type: Grant
    Filed: June 10, 2004
    Date of Patent: June 27, 2006
    Assignee: Ricoh Company, Ltd.
    Inventor: Hiroshi Mizusawa
  • Publication number: 20060039726
    Abstract: A cleaning device, a process cartridge, an image forming apparatus, and toner to maintain improved cleaning performance for a long time. The cleaning device includes a cleaning blade, a lubricant applying part, and a toner removing part. The cleaning blade is disposed in contact with a surface of an image bearing member. The lubricant applying part coats a solid lubricant on the surface of the image bearing member, and is disposed in an upstream side from the cleaning blade with respect to a rotational direction of the image bearing member. The toner removing part removes toner particles, and is disposed in an upstream side from the lubricant applying part with respect to the rotational direction of the image bearing member.
    Type: Application
    Filed: August 22, 2005
    Publication date: February 23, 2006
    Inventors: Takeshi Shintani, Takuzi Yoneda, Ken Amemiya, Takaaki Tawada, Tokuya Ojimi, Toshio Koike, Yuji Arai, Masanori Kawasumi, Masami Tomita, Hideyo Watanabe, Satoshi Takano, Haruji Mizuishi, Hiroshi Ono, Hiroshi Mizusawa, Satoshi Hatori, Takeshi Tabuchi, Akira Fujimori, Kaoru Yoshino
  • Patent number: 6898383
    Abstract: A control system for an image forming device includes a sensor mounted on an optical path unobstructed by elements that are subject to wear for detecting a time varying signal representing reflected light from both a photoconductive element and a transfer sheet internal to the image forming device, a memory storing reference values, and a controller to control an image forming operation based on the reference values stored in the memory and the time-varying signal received from the sensor. The controller reads the time-varying signal from the sensor and compares the time-varying signal read to the reference values to determine a condition of the image forming device.
    Type: Grant
    Filed: July 2, 2003
    Date of Patent: May 24, 2005
    Assignee: Ricoh Company, Ltd.
    Inventors: Mayumi Ohori, Masaru Tanaka, Haruji Mizuishi, Hiroyuki Ohkaji, Kenzo Tatsumi, Hiroshi Mizusawa, Ken Amemiya, Hideki Zenba, Fumio Kishi
  • Publication number: 20050019057
    Abstract: A cleaning device includes a brush roller that removes deposit from a surface of a member to be cleaned by rotating due to a movement of the surface of the member. The brush roller includes a rotary shaft element and a brush provided on the rotary shaft element. The brush abuts the surface of the member due to a weight of the brush roller. The brush includes filaments, and the brush roller satisfies the inequation Y/X?2.8, where Y is a diameter (denier) of each of the filaments, and X is a length (mm) of each of the filaments.
    Type: Application
    Filed: June 10, 2004
    Publication date: January 27, 2005
    Applicant: RICOH COMPANY, LTD.
    Inventor: Hiroshi Mizusawa
  • Patent number: 6807390
    Abstract: An image forming apparatus includes a plurality of photoreceptors and an intermediated transfer body through which toner images on the photoreceptors are transferred to a recording medium. The image forming apparatus also includes charging members provided in contact with or adjacent to the respective photoreceptors, and further includes at least one cleaning unit that contacts the charging member and removes foreign substance from the surface of the charging member.
    Type: Grant
    Filed: April 3, 2003
    Date of Patent: October 19, 2004
    Assignee: Ricoh Company, Ltd.
    Inventors: Takeo Suda, Shinichi Kawahara, Masanori Kawasumi, Ken Amemiya, Hiroshi Ono, Hiroshi Mizusawa
  • Publication number: 20040146309
    Abstract: The image forming apparatus comprises a photoconductor, a latent electrostatic image forming unit for forming a latent electrostatic image on the photoconductor, a developing unit for developing the latent electrostatic image using a developer comprising a toner to form a visible image, a transfer unit for transferring the visible image to a recording medium, a cleaning unit for removing the developer remained on the photoconductor surface and a developer amount detection unit for detecting developer amount adhering to the photoconductor surface by a reflecting photosensor, wherein the developer stirring time per copy when one copy is made from an original, is 2 to 6 times the developer stirring time per copy when two or more copies are made from the original, wherein the toner comprises at least a binder resin and a wax, and the dynamic frictional coefficient of the toner is 0.15 to 0.45.
    Type: Application
    Filed: January 15, 2004
    Publication date: July 29, 2004
    Inventors: Bing Shu, Mitsuo Aoki, Haruji Mizuishi, Mikio Ishibashi, Masaru Tanaka, Shinji Tamaki, Hiroshi Mizusawa, Shin Hasegawa
  • Publication number: 20040131405
    Abstract: A cleaning apparatus includesa brush member to be brought into contact with a member to be cleaned to remove toner particles attached to the member. The brush member includes a conductive material.
    Type: Application
    Filed: October 17, 2003
    Publication date: July 8, 2004
    Inventor: Hiroshi Mizusawa
  • Publication number: 20040071475
    Abstract: A control system for an image forming device includes a sensor mounted on an optical path unobstructed by elements that are subject to wear for detecting a time varying signal representing reflected light from both a photoconductive element and a transfer sheet internal to the image forming device, a memory storing reference values, and a controller to control an image forming operation based on the reference values stored in the memory and the time-varying signal received from the sensor. The controller reads the time-varying signal from the sensor and compares the time-varying signal read to the reference values to determine a condition of the image forming device.
    Type: Application
    Filed: July 2, 2003
    Publication date: April 15, 2004
    Inventors: Mayumi Ohori, Masaru Tanaka, Haruji Mizuishi, Hiroyuki Ohkaji, Kenzo Tatsumi, Hiroshi Mizusawa, Ken Amemiya, Hideki Zenba, Fumio Kishi
  • Publication number: 20030215259
    Abstract: An image forming apparatus includes a plurality of photoreceptors and an intermediated transfer body through which toner images on the photoreceptors are transferred to a recording medium. The image forming apparatus also includes charging members provided in contact with or adjacent to the respective photoreceptors, and further includes at least one cleaning unit that contacts the charging member and removes foreign substance from the surface of the charging member.
    Type: Application
    Filed: April 3, 2003
    Publication date: November 20, 2003
    Inventors: Takeo Suda, Shinichi Kawahara, Masanori Kawasumi, Ken Amemiya, Hiroshi Ono, Hiroshi Mizusawa
  • Patent number: 6628903
    Abstract: An image forming apparatus with a sensing control system having an optical sensor and a control device. A detected object is recognized by using the difference of an output characteristics correspond to a quantity of reflected light. Thus, one or more detected objects may be precisely detected by the one optical sensor.
    Type: Grant
    Filed: July 27, 2000
    Date of Patent: September 30, 2003
    Assignee: Ricoh Company, Ltd.
    Inventors: Mayumi Ohori, Masaru Tanaka, Haruji Mizuishi, Hiroyuki Ohkaji, Kenzo Tatsumi, Hiroshi Mizusawa, Ken Amemiya, Hideki Zenba, Fumio Kishi
  • Patent number: 6266501
    Abstract: An image-forming apparatus includes an image-bearing device that holds an electrostatic latent image and a toner image thereon, and a developer container that contains and agitates a developer having at least a toner. The image-forming apparatus also includes a developer-bearing device that carries the developer to develop the electrostatic latent image on the image-bearing device, and a density sensor that detects an optical density of a surface of the image-bearing device and a toner image on the image-bearing device. Further, the image-forming apparatus includes a developer seal that seals the developer in the developer container, wherein the seal is disposed between the developer container and the developer-bearing device, and an actuator configured to actuate the developer container and the developer-bearing device.
    Type: Grant
    Filed: January 14, 2000
    Date of Patent: July 24, 2001
    Assignee: Ricoh Company, Ltd.
    Inventors: Haruji Mizuishi, Masaru Tanaka, Kenzo Tatsumi, Ken Amemiya, Toshitaka Yamaguchi, Hideki Zemba, Noriyuki Usui, Mayumi Ohori, Hiroshi Mizusawa
  • Patent number: 6160969
    Abstract: An image forming apparatus transfers a toner image from a photoconductive image carrier to a recording medium with a transfer roller and senses the density of a particular toner pattern formed on the image carrier with an optical sensor. A voltage of a first polarity opposite the polarity of the toner is applied to the transfer roller when the toner image is to be transferred to the recording medium. A voltage of a second polarity identical to the polarity of the toner is applied to the transfer roller when the toner pattern is to be moved between the image carrier and the transfer roller. Thus, even when a toner pattern is brought to the transfer roller, the transfer roller is not released from the photoconductive element.
    Type: Grant
    Filed: August 17, 1998
    Date of Patent: December 12, 2000
    Assignee: Ricoh Company, Ltd.
    Inventors: Kouji Ishigaki, Haruji Mizuishi, Masaru Tanaka, Hiroyuki Ohkaji, Kenzou Tatsumi, Hiroshi Mizusawa, Ken Amemiya, Hideki Zenba, Mayumi Ohori
  • Patent number: 6148161
    Abstract: An image forming apparatus includes an image carrier and a developing device to develop a latent image formed on the image carrier by applying two-component developer, including toner, onto the latent image. The developing device includes a developing part containing the two-component developer and a developer stirring device to stir the two-component developer. A toner supplying device supplies toner to the developing part of the developing device, and a toner density detection device detects a toner density of the two-component developer in the developing device. A toner control device calculates a difference between an output value VT of the toner density detection device and a criterion value VTref for controlling the toner density of the two-component developer and controls the toner supplying device based upon the difference.
    Type: Grant
    Filed: October 12, 1999
    Date of Patent: November 14, 2000
    Assignee: Ricoh Company, Ltd.
    Inventors: Noriyuki Usui, Ken Amemiya, Haruji Mizuishi, Mayumi Ohori, Masaru Tanaka, Kenzo Tatsumi, Toshitaka Yamaguchi, Hideki Zemba, Hiroshi Mizusawa
  • Patent number: 6144822
    Abstract: An image forming apparatus is provided, which includes an image bearing member, a transfer roller having a shaft for transferring an image on the image bearing member to a transfer sheet, a bearing mechanism for supporting the shaft, a discharging device for discharging the transfer, and a joint mechanism which mechanically connects the discharging device with the transfer roller at both ends of the shaft. Both of the transfer roller and the discharging device can be integrally detached from and attached to the image forming apparatus without detaching/attaching the bearing mechanism, by use of a handle. Therefore, an operation for replacing the transfer roller and the discharging device can be performed easily.
    Type: Grant
    Filed: September 30, 1999
    Date of Patent: November 7, 2000
    Assignee: Ricoh Company, Ltd.
    Inventors: Toshitaka Yamaguchi, Masaru Tanaka, Hiroshi Mizusawa, Kenzo Tatsumi, Ken Amemiya, Haruji Mizuishi, Hideki Zemba, Noriyuki Usui, Mayumi Ohori
  • Patent number: 6144811
    Abstract: A image forming apparatus with a sensing control system having an optical sensor and a control device. An detected object is recognized by using the difference of an output characteristics correspond to a quantity of reflected light. Thus, one or more detected objects may be precisely detected by the one optical sensor.
    Type: Grant
    Filed: February 2, 1999
    Date of Patent: November 7, 2000
    Assignee: Ricoh Company
    Inventors: Mayumi Ohori, Masaru Tanaka, Haruji Mizuishi, Hiroyuki Ohkaji, Kenzo Tatsumi, Hiroshi Mizusawa, Ken Amemiya, Hideki Zenba, Fumio Kishi
  • Patent number: 6128449
    Abstract: An image forming apparatus includes a charging element configured to apply a charging voltage to an image bearing member to charge the image bearing member, an optical writing device configured to form a latent image on a charged surface of the image bearing member charged by the charging element, a developer bearing member which carries developer including toner having a same polarity as that of the charging voltage to the image bearing member and which applies the toner to the latent image on the image bearing member to form a toner image when a developing bias voltage is applied thereto, and a control device which controls application of the charging voltage by the charging element and application of the developing bias voltage to the developer bearing member so as to increase an absolute value of the charging voltage to the image bearing member and an absolute value of the developing bias voltage to the developer bearing member to a predetermined value in a plurality of steps, respectively and wherein the
    Type: Grant
    Filed: October 5, 1998
    Date of Patent: October 3, 2000
    Assignee: Ricoh Company, Ltd.
    Inventors: Hideki Zenba, Masaru Tanaka, Haruji Mizuishi, Hiroyuki Okaji, Kenzo Tatsumi, Hiroshi Mizusawa, Ken Amemiya, Mayumi Ohori
  • Patent number: 6085062
    Abstract: An electrophotographic image forming apparatus is disclosed which is provided within a cleaning device with a rotative conveying member for conveying a residual toner after removal thereof from a photoreceptor up to an inlet of a toner dropping path while rotating. Within the toner dropping path is disposed a toner bridge preventing member for preventing the formation of a toner bridge in the same path. The toner bridge preventing member is driven by the rotative conveying member so as to reciprocate substantially in parallel with the toner dropping direction.
    Type: Grant
    Filed: April 12, 1999
    Date of Patent: July 4, 2000
    Assignee: Ricoh Company, Ltd.
    Inventors: Haruji Mizuishi, Ken Amemiya, Hiroshi Mizusawa, Hiroyuki Ohkaji, Mayumi Ohori, Masaru Tanaka, Hideki Zenba, Kenzou Tatsumi